The present invention relates to methods for fabricating absorbent articles, including applying selected material to an absorbent article web sausage. More particularly, the methods include cutting a waist opening in the web sausage and applying a waist piece to cover the waist opening. The methods further include cutting leg cut-outs on each side of the web sausage and applying leg cuffs to cover the leg cut-outs.
Conventional methods of making absorbent articles, such as disposable diapers are well known in the art These methods usually rely on attaching leg cuffs, containment flaps, and other elements to the absorbent article as continuous webs of attachment material. Thus a .continuous strip of material, such as leg cuff material, is continuously applied to the shell of an absorbent article. This simple method allows for high speed forming of absorbent articles. Since material is continuously applied to the absorbent article shell, a portion of the material may be wasted or unnecessarily applied to portions of the absorbent article where it is not required. Further, the overall design and appearance of the absorbent article is limited by this method of manufacture.
In previous proposals, cuff materials were intended to be placed between the liner and the outer cover material. The difficulty of this proposal was that cutouts had to be cut in both the bodyside liner and the outer cover material prior to lamination and then accurately registered to entrap the cuff material. This process was considered too difficult to be cost effective and therefore was never practiced commercially. Applicant""s process greatly reduces the complexity by placing waist and leg cuffs on an absorbent article web sausage after the bodyside liner, absorbent core and outer cover have been integrally secured to each other with the leg and/or waist openings cut out to form the unitary web sausage prior to cuff application.
Methods for making a series of absorbent articles from an absorbent article web sausage are disclosed. A first embodiment comprises the steps of cutting at least one waist opening in a central region of the web sausage; applying adhesive to one of a waist piece material, and the web sausage about the waist opening; placing the waist piece material on a waist piece applicator and cutting the waist piece material to sever a waist piece therefrom, the waist piece having dimensions sufficiently large to cover at least one dimension of the waist opening; placing the waist piece over the waist opening; and securing the waist piece to the web sausage.
In most embodiments, the method includes moving the web sausage along a processing line on a conveyor, the conveyor supporting the web sausage before the waist piece is applied to the web sausage.
In some embodiments, the method includes the step of severing the web sausage in a direction substantially transverse to the length of the web sausage and across the waist piece, thereby severing, from the web sausage, an absorbent article including a portion of the waist piece. The remainder of the waist piece remains with the web sausage. The portion of the waist piece remaining with the web sausage forms a respective front waist or rear waist portion for the next successive absorbent article in the web sausage.
In most embodiments, the steps are repeated for individual sections of the web sausage to form a series of absorbent articles that are severed from the web sausage.
In some embodiments, the method includes placing waist pieces over spaced waist openings, the waist pieces being spaced from each other on the web sausage.
In most embodiments, the method includes the step of stretching the waist pieces, and securing the waist pieces to the waist openings in the stretched condition. The waist pieces preferably are stretched to a dimension representing about 5% to about 95% of the respective stretch-to-stop dimensions.
In some embodiments, the method includes ultrasonic bonding that finishes raw edges of the waist piece.
In some embodiments, the method includes moving the web sausage along a processing line from a first work station to a second work station to perform at least one step subsequent to cutting the waist opening.
Another embodiment discloses a method of applying leg cuffs to an absorbent article web sausage comprising the steps of: cutting leg cut-outs on opposing sides of the web sausage; applying adhesive to the extensible leg cuff materials and the web sausage adjacent the leg cut-outs; placing the extensible leg cuff materials on a leg cuff applicator and cutting the extensible leg cuff materials to sever extensible leg cuffs therefrom, the leg cuffs having dimensions longer than the lengths of the leg cut-outs; placing the extensible leg cuffs over the leg cut-outs; and securing the extensible leg cuffs to the web sausage.
In some embodiments, the method includes placing leg cuffs over spaced ones of the leg cut-outs, the leg cuffs being spaced from each other along the length of the web sausage on the processing line. The method can also include the step of stretching the leg cuffs, and applying the leg cuffs on the leg cut-outs in the stretched condition. The leg cuffs preferably are stretched to a dimension representing about 5% to about 95% of the respective stretch-to-stop dimensions.
In yet another embodiment, the invention comprehends a method for making an absorbent article comprising the steps of: joining a bodyside liner, an absorbent core, and an outer cover to form an absorbent article web sausage; cutting leg cut-outs on opposing sides of the web sausage and cutting a waist opening in the web sausage; applying adhesive to one of a waist piece material, and the web sausage about the waist opening; placing the waist piece material on a waist piece applicator and cutting a waist piece to a set of dimensions sufficiently large to cover the waist opening; placing the waist piece over the waist opening; and securing the waist piece to the web sausage.